Evidence for a liquid silicate layer atop the Martian core

Seismic data from the InSight mission suggests a Martian core significantly lighter than pure liquid iron, implying substantial light elements. However, this conflicts with cosmochemical constraints on volatile element availability. This paper proposes a molten silicate layer overlying a smaller, denser liquid core. Inversion of seismic data reveals a core radius of 1,675 ± 30 km and density of 6.65 ± 0.1 g cm⁻³, with a 150 ± 15 km thick silicate layer (density 4.05 ± 0.05 g cm⁻³). This model reconciles geophysical and cosmochemical data, suggesting a core with 85-91 wt% iron-nickel and 9-15 wt% light elements.

A. Khan, D. Huang, C. Durán, P. A. Sossi, D. Giardini, M. Murakami